This may seem like a no brainer, but I want to change out the fluid on my 01 C5 it only has about 16000 miles on her, so due to tiime I thought it would be a good idea. My question is does the 01 C5 have a drain plug or do you have to remove the cover. The dealer wants 160.00. They said they remove the cover to inspect the parts...I don't want the cover removed because it does not leak and I know once the stealership does work it probably will start.

 

It is probably the rear cover, which isn't what usually leaks on these cars, but I doubt for $160 they even do that. Honestly, at 16K I wouldn't mess with it, but if it makes you feel better go for it. Do it yourself, it is easy. Jack the car up (level, you will see why later), you will see on the bottom there is a drain plug. Drain it out, and let it sit for a few because it will take awhile to drain. Put the plug back in. There is another plug on the back on the passenger side. Pull it out, and you want 2 bottles of rear end juice (I like the Redline 75w90 myself) and for good measure get a tube of limited slip additive. You will probably want to go to the parts store and get a cheap fluid transfer pump for this part. With the car level like I mentioned before, start pumping fluid in there. When the first bottle gets halfway down, pour the limited slip additive in that bottle, and continue pumping away. Move on to the second bottle, and keep filling. You will get most of the second bottle in, and fluid will start coming out the fill hole. Stop at this point, let it stop running out, put the plug back in place, wipe the rear down where the fluid dripped, and you're done. Should cost you about $35 in fluids, including the cost of the cheap transfer pump.

 

Thats what I thought.... thanks for the reply....just wanted to double check.

 

Ummm, If you do what Mike says, you'll end up blowing something up.

just kidding mike

 

Mike,
I use the Redline 75/90 too and it already has limited slip additive in it. I've never added additional to either my DD or my track car and it works fine. The Redline 75/90ns is the one that needs additive.
Doug

 

Hi pm0084 -

There is a drain plug on the differential.



Here is a link to some pictures that may help -

http://www.iammoon.com/images/c5tech/diffoil/

best regards -

mqqn

 

The local Chevy dealer just drained and refilled mine (including additive) for $89. Check with another dealer if you want it done for you.

 

Just make sure you can get the fill plug loose before you remove the drain plug.

 

Would not be good to drain old out and not be able to get the new in.

 

diff fluid is good for 50,000 miles. Save your money for gas

 

Didn't mike just blow up his rear end??!! JK mike. Sorry to hear about it, and thanks for the scoop. I'm about due for a little differential PM myself.

 

Just finished a 500 mile break-in on my new 3.73s.
Would it be wise to replace the differential fluid?
Ed

 

Hi Ed -

Did the vendor of the diff recommend that?

It surely would not hurt anything, and at two quarts it would not cost a lot if you wanted to do it.

There would be no reason to do this from the perspective of contaminants or metallic shavings from gears polishing in - if the rear is set up properly - in my opinion.

best regards -

mqqn

 

I got around to doing my fluid change today everything went smooth, thanks for the post and great pictures. I went with Mobil 1 and some LSD additive if anyone was interested.
Thanks again

 

Hi Paul -

Glad the pics helped.

I have pics of the manual trans fluid change as well, just change diffoil to transoil in the link I posted.

best regards -

mqqn

 

What size bit do you need to get the fittings off the differential?

 

Hi Sigforty -

It is a 10mm hex wrench (allen wrench...)

best regards -

mqqn

 

I Remember With My C4 They Recommended 2 Tubes Of The Limitted Slip Additive. Has This Changed With The C5?

Thanks

 

Hi UWEBABY -

It depends on what you are adding - GM does specify adding friction modifier into the C5 differential, but some of the aftermarket gear lubes already contain this additive.

best regards -

mqqn